Wheel chock restraint system

ABSTRACT

Wheel chock restraint system comprising a wheel chock, a supporting element mounted on the ground near a loading dock and a support assembly connected by one end to the wheel chock and by another end near the loading dock. A base portion of the chock is provided with first engagement elements and the supporting elements are provided with corresponding second engagement elements, cooperating to create a retention force to prevent the chock from sliding away from the wheel of a vehicle attempting to depart prematurely. The first engagement elements comprise teeth extending downwardly under an angle and the second engagement elements are stoppers extending upwardly from the supporting element. This system also comprises an anti-theft locking device; which, together with the first and second engagement elements, securely locks the chock on the wheel of the vehicle to prevent any unauthorized removal of the chock and theft of the vehicle.

This is a divisional application of the previously filed applicationSer. No.: 10/370,771 filed on Feb. 24, 2003, now U.S. Pat. No.7,032,720.

The present invention relates to wheel chocks, and more particularly toa wheel chock restraint system provided to engage the wheel of a truckto prevent it from moving away from the loading dock during loading andunloading.

Loading and unloading operations are hazardous for fork lifts enteringand exiting the truck trailer. It is imperative that a truck remainimmovably docked to the loading dock to prevent moving fork lifts fromfalling through the space created if a truck trailer moves truck awayfrom the loading dock during loading and unloading.

There are known two main kinds of restraint systems: ICC bar restraintsystems to prevent the truck from moving away from the dock, and wheelrestraint systems. However, while the first system is suitable for amajority of trailers, there are several configurations of trucks thatcannot be secured by such ICC bars. Besides, ICC bars are built toabsorb a rear impact with another truck and are not designed to resist astrong pulling force. In view of this fact, this system does not preventthe truck from moving away from the loading dock. The second categoryincludes manual and mechanical chocks. Manual placement of a chockpresents different problems, such as: chocks may be displaced, damaged,lost, or stolen. They also may slip on icy, oily or dusty surfaces andare often difficult to remove from their operational position becausethey may be wedged very tightly under the trailer's wheel. Very often,chocks are removed before the loading operation is complete, thuscreating a dangerous situation where the vehicle can depart prematurelyor slide away from the dock as heavy fork lifts enter the trailer. Also,docked trailers can be stolen mostly after business hours. In a lot ofcases, targets for theft are trailers loaded with valuables, such asalcohol, beer, cigarettes, or any other goods.

Often, standard chocks are placed too far from the wheel to be effectivebecause they can jam and become very difficult to remove; for example,when an empty trailer becomes heavily loaded, the weight on the tiresmakes them extend sideways, resulting in the wheel to sit on the chock.A tire can also jam into the chock if the air ride suspension causes aslight movement of the trailer when depressed. Standard chocks aresometimes left lying beside the wheel due to negligence.

Mechanical wheel chock systems are more effective than manual systems.However, they may be buried in the driveway during installations underground, are expensive to install, require a drainage system to preventthem to be filled with water. They also are not very easy to service andhave to travel a substantial distance from storage into operativeposition. Other mechanical chocks which are mounted on the surface maybe affected by winter and become an obstacle during snow removal Theymay interfere with the tail gate of the truck or truck's undercarriage,and are inoperable with many types of vehicles.

This invention is related to my Canadian application No. 2,164,738,describing a wheel chock handling system including a movable armattached by one end to a loading dock and another end to a wheel chock.The arm consists of a front arm and a rear arm A return spring isattached between the loading dock and the upper end of the rear arm.

The major disadvantage of said system was its effective range: becausethe spring was attached to the rear arm, the more said arm was extended,the more tension was created in the spring making the handling of saidthe chock attached to said arm harder and harder after 7 feet ofextension of the arm from the loading dock. At the distance of 10 to 14feet, handling the arm required a great deal of effort and force.

The present invention eliminated these problems and provides an improvedsystem allowing a very easy and effortless way of handling heavy chocks.

SUMMARY OF THE INVENTION

The primary object of the present invention is a wheel chock restraintsystem provided to restrain the movement of a vehicle away from aloading dock during loading and unloading operations. The systemcomprises a wheel chock having an engagement means adapted to cooperatewith a corresponding engagement means of a support plate mounted on theground. The chock is attached to a movable arm attached to the loadingdock and adapted to assure secure positioning of the chock under thewheel of the truck. The arm is provided with a tension meansfacilitating easy manipulation of the chock and placing the arm into thestorage position.

Another object of the present invention is a sensor means provided todetect the wheel and to facilitate proper placement of the chock underthe wheel.

Yet another object of the present invention is to provide a wheel chockequipped with a jamming or locking mechanism that will prevent anunauthorized chock removal during loading and unloading or during afterbusiness hours. Such jamming mechanism is activated from inside of thebuilding. Jamming mechanism is incorporated within the chock.

Still another object of the present invention is to prevent solidjamming of the chock by means of a locking element keeping a slightdistance between the wheel and the chock.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic side view of the first embodiment of thepresent invention.

FIG. 2 shows a perspective view of the wheel chock restraint system ofFIG. 1.

FIG. 3 shows a schematic side view of a second embodiment of the presentinvention.

FIG. 4 (a, b, c) shows different modifications of the configuration ofthe base portion of the chock and the support plate.

FIG. 5 (a, b, c) shows perspective views of the modification of sensorsinstalled on the chock.

FIG. 6 shows a side view on the chock provided with an anti-theft meanslocking device.

FIG. 7 shows a schematic block diagram of elements controlling chock ofFIG. 6.

FIG. 8 shows a perspective view according a third embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

Referring to drawings, FIGS. 1 and 2 show the first embodiment of thepresent invention comprising a wheel chock 1 attached to a wheel chocksupport means including a movable arm A consisting of a front arm 10pivotally attached to a rear arm 12. Rear arm 12 is pivotally attachedto a loading dock 27 by means of a pivot or bracket 14. A tension meanssuch as an extension spring 16 is attached by one end to a pivot 14 andby another end to an upper portion of the front arm 10 by means of acable or steel rod 17. Pivot 14 allows the arm A to be rotated left andright and up and down, and to move it into storage position, in closeproximity to the dock face (not shown) when not in use.

A supporting element 3 is fixed on the ground in the vicinity of theloading dock and comprises an elongated plate long enough to spread atleast under one axle of a truck 9 during loading operation to facilitatea proper engagement of a wheel chock 1 with the plate 3. A base portionof the chock 1 is provided with a first engagement means or teeth 2which are adapted to cooperate with the corresponding second engagementmeans or stoppers 4 located on plate 3.

Once the vehicle 9 is backed to the dock 27, the truck driver manuallysets the chock 1 by means of a handle 35 mounted on the front arm 10 toengage the chock 1 with a wheel 8. The spring 16 attached from the pivot14 to the upper portion of front arm 10 by means of cable 17 assists themanipulation of the driver of the movable arm A. In this case, on onehand the retention force created by engagement of teeth 2 of chock 1 andstoppers 4 of the plate 3 is directed away from the loading dock 27 andprevents the chock 1 from sliding away from the wheel 8 of the truck 9when said truck makes attempts to depart prematurely from the dock 27.On the another hand, arm A creates an engagement force directed towardsthe loading dock 27 and presses chock 1 against the wheel 8. Such acombination of two forces allows to assure a secure positioning of truck9 during loading and unloading, which is a very advantageous feature ofthe present invention.

Front arm 10 is pivotally attached to the chock 1 by means of a lowerjoint 13 and front arm 10 is pivotally connected to rear arm 12 by meansof upper joint 11. It should be emphasized that upper joint 11 may be ofany possible configurations, such as a universal joint, bracket with apivot or any other means which facilitates effortless pivoting of botharms. The most important feature of the present embodiment is the factthat spring 16 is attached to the upper portion of the front arm 10.Such arrangement allows very easy manipulation of the system because themore arm A extends, the more spring 16 pulls and consequently chock 1become lighter and lighter due to the leverage effect. This feature is asubstantial improvement over my previous arrangement discussed abovewherein spring was attached to the rear arm However, the presentinvention is not restricted to use of spring 16 and any other tensionmeans may be used instead to the same purpose.

Pivot 14 is attached to the dock face 27 by means of an anchor plate 15.In the present invention, the engagement means of the chock comprises aplurality of angled teeth 2 extending downwardly from the base portionof the chock 1. Engagement means of the plate 3 comprises a plurality ofextending upwardly stoppers 4. However, it must be emphasized that thepresent invention is not restricted to such an arrangement, and anyother possible equivalents may be used instead for the same purpose. Inuse, chock 1 should be positioned in such a way that teeth 2 should bedirected away from the loading dock 27.

Chock restraint system of FIG. 1 is also provided with different kindsof sensors facilitating secure loading and unloading procedures. Sensor18 installed on the pivot 14 is provided to detect the extendingmovement of the arm A during placement of the chock 1 under the wheel 8.Sensor 6 installed on the chock 1 is provided to detect the presence ofthe wheel 8 at the moment said wheel engages the chock. This sensor 6 isa very advantageous feature of the present invention. When the arm isremoved from storage position, sensor 18 will send a signal toilluminate a visual indicator 23 to warn the dock workers and drivers.Visual indicator 23 will be also illuminated in response to both sensors18 and 6 to ensure that the arm A is utilized and that the wheel 8 isproperly engaged. Detecting sensors could be of any possiblearrangements, such as non-contact sensors (photocell), mechanicaldetectors with contact arm, or any other equivalent arrangement.

Truck presence detector 19 may be installed around the dock to detect avehicle when arriving in the vicinity of the dock 27. Such detector mayalso be of contact or non-contact (photocell) arrangement, and isdesigned to sense the vehicle a few inches from the dock. Using thecontrol panel 24, the vehicle detector 19 can be interlocked with othersensors, such as a restraint sensor 6 or 18 and dock leveller sensor 21.Movement of the truck during loading and unloading operations cantrigger a loud alarm 22 to make the truck drivers and fork liftoperators aware of danger. Dock leveller detector 21 is installed underthe dock leveller 26 and is activated by said dock leveller 26. Loadingentrance 27 is also provided with a dock seal 28, dock bumper 29 andinterior lights 25 used for the same function as exterior lights 23.

In operation, when the truck backs into position with loading dock 27,wheel 8 rolls over the supporting plate 3. Once the truck 9 is backed upto dock 27, the truck driver will manually set the chock 1 by means ofhandle 35 mounted on the front arm 10 to engage with the wheel 8. Thespring 16 attached from the pivot 14 to the upper portion of the frontarm 10 by cable 17 will assist the manipulation of the arm A by thedriver to allow easy handling. The dock leveller 26 spans the gapbetween the bed of the truck 9 and the floor to allow forklifts to go inand out of the truck 9, which is backed to the dock 27 against the dockbumper 29.

The sensor 7 or sensor 6 will sense the wheel 8 to ensure a properpositioning of the chock 1, and the detector 18 of pivot 14 will signalthe use of the extendable arm A. Proper positioning of the chock 1 isfacilitated by articulations of pivot 14, upper joint 11 and lower joint13. The truck presence detector 19 mounted on the bracket 20 will sensethe truck 9 when approaching 4-5 inches from the dock bumper 29. In casethe truck 9 will start to move away during the loading operation, dockleveller detector 21 interlocked with the dock leveller 26 together withthe truck presence detector 19 will trigger alarm 22. All followingdetectors 6, 7, 18, 19 and 21 are operatively connected to the controlpanel 24 which will illuminate lights 23 and 25 to indicate when theloading operation is safe.

Such arrangement of using detectors to indicate the right setting of thechock is also a very important feature of the present invention becauseit eliminates all possible premature movements of the truck from theloading dock and prevents any accidents.

Chock 1 is made from high tensile weather resistant galvanized steelwhich is many times harder than conventional steel. All weather chockcombined with non-skid plate can provide 60,000 lbs. of restrainingforce.

FIG. 3 shows a second embodiment of the present invention whereininstead of one spring there are used two springs 16 a and 16 b. In thisembodiment spring 16 b is attached between the pivot 14 and the rear arm12 by means of a protrusion 30. Second spring 16 a is attached by oneend to the pivot 14 and by another end to the upper portion of the frontarm 10 by means of the cable 17. Second spring 16 a is provided to pullthe upper portion of the front arm 10 to facilitate easy handling of abig chock. The sensor 7 senses when wheel 8 engaging the chock 1 in thesame manner as previous embodiment.

For both embodiments shown on FIG. 1 and FIG. 3 the attachment point ofcable or rod 17 depends upon the length of the front arm 10, weight ofsaid arm 10 and chock 10 and the strength of the tension means.

FIGS. 4 a, b and c show different modifications of the configuration ofthe base portion of the chock 1 and stoppers 4 of the supporting plate3. FIG. 4 a shows base portion of the chock provided with a plurality ofangled teeth 2 extending downwardly. Stoppers have configuration of aplurality of angled rods 4 a extending upwardly from the plate 3 andinclined under an angle corresponding to the angle of the teeth 2.Stoppers 4 a are mounted transversally along the plate 3. Suchcomplimentary angled configuration of teeth 2 and stopper 4 allows avery secure engagement preventing the chock 1 from tumbling and slidingwhen the truck 9 is exerting a strong pull-out force.

FIG. 4 b shows angled teeth 2 of chock 1 cooperating with cylindricalstoppers 4 b mounted transversally along the plate 3. FIG. 4 c showsangled teeth 2 of chock 1 engaging a plurality of transversal grooves 4c formed in the plate 3. Preferably grooves 4 c are cut in angle tofacilitate better engagement with teeth 2.

Teeth 2 of chock 1 have a hook-shaped configuration and are inclinedunder the angle in the range between 0 and 90 degrees. Preferably, theangle is chosen between 5 and 30 degrees.

FIGS. 5 a, b, and c show different modifications of the sensor 6installed inside the body of the chock 1. FIG. 5 a shows an air-pressuresensitive detector comprising an air balloon 31 provided with an airsensor gauge 32 which is activated when the wheel 8 engages the chock 1.

FIG. 5 b shows a spring-activated sensor comprising a spring pivot 33,spring lever 34 and switch 33 a. When wheel 8 engages the chock, it willrotate spring lever 34 activating the switch 33 a. Spring 33 is adaptedto bring lever 34 into the position, thus allowing the chock 1 to be setfrom any angle.

FIG. 5 c shows an electronic sensor 36 installed by means of steel orrubber bracket 37 to shield it from strong vibration. Due to its savepositioning inside the chock 1, sensor 36 is able to sense the wheeleven when it is wet or during toughest weather conditions and to assureproper positioning of the chock 1. Such sensor can be wired, working onradio frequency or may be operated by any other means. The sensor 36will detect the wheel 8 when properly set and send a signal to thecontrol panel 24 that will activate light 23 or interlock with dockleveller 26. It also can be linked to the truck presence detector 19.

FIGS. 6 and 7 show yet another modification of the chock 1 provided withan anti-theft arrangement comprising a locking mechanism activated byremote activating means that can lock the chock 1 against the wheel 8.The locking mechanism consists of a locking element 38 which is adaptedto slide within a support guide 39. The movement of element 38 isprovided by means of an air cylinder 40 having a piston 41, connectingrod 42 and spring 43 which is provided to exert a minimum tension toactivate element 38. When locking element 38 is activated, it makescontact against the tire 8. In this case, the combination of oppositeforces created by teeth 2 of chock 1 engaging stoppers 4 of plate 3 andforces created the locking element 38 tightly abutting tire 8 facilitatecomplete locking of chock 1 against wheel 8, which is a substantialadvantage of the present invention.

FIG. 7 shows a complete assembly provided to activate the lockingfunction of the mechanism shown on FIG. 6. As it was mentioned above,the locking element 38 slides within support guide 39 and is activatedby means of air cylinder 40. The compressed air for cylinder 40 isproduced by an air compressor 44 located inside of the chock andnecessary power is supplied by a power supply 65. Compressor 44 isactivated by a signal transmitted from switch or sensor 45 or an alarmsystem switch 67 located in the building. A pressure switch 47 installedon the air line between switch 45 and air compressor 44 is provided tomaintain a steady pressure in cylinder 40. A release valve 48 is placedin the air input conduit 49 to release air from cylinder 40 when poweris cut by switch 45 which is done to release air and to allow thelocking element 38 to disengage the wheel 8. Such arrangement provides avery important function of the present invention: to control the releaseof the wheel of a docked vehicle when the loading is complete and tofacilitate locking of wheel after business hours. After business hours,the alarm system is ‘on’ and the signal from switch 45 is replaced byone transmitted from the alarm system or switch 67 controlling thelocking of the wheels of docked vehicles to prevent said vehicles frombeing stolen.

A differential pressure switch 50 is installed on the air input conduit49 and is connected to the control panel 51 located in the building.Control panel 51 is connected to the alarm (anti-theft) system or switch67 also located within the building. The chock 1 cannot be removed onceswitch 50 is activated by signal transmitted from the alarm system. Ifvariation is sensed in pressure applied to the chock 1, the alarm systemcan be activated automatically.

A green light 52 inside the building is activated by means of thepressure switch 53 installed on the input air conduit 49 to controlcorrect pressure inside the cylinder 40 and to properly position lockingelement 38. A red light 54 is activated by means of a detector 55 insidethe chock 1. Detector 55 is activated by means of a stopper 56 attachedto locking element 38. Detector 55 sends signal to a relay 57 that cutspower supplied to green light 52. In this case, stopper 56 will activatedetector 55 only when locking element 38 does not make the necessarycontact with the wheel 8 and extends to its limit. Red light 54 can warnof non-safe operation. An audible means can be added to signal danger,for example when chock 1 is positioned too far from the wheel 8 orbeside it. A one-way valve 60 can be installed between air compressor 44and pressure switch 47.

When loading operation takes place, fork lifts going inside the dockedvehicle may cause some movement affecting change in pressure applied tolocking element 38. To control this situation, an air reserve tank 58equipped with a safety valve 59 will supervise such variation of thepressure and will prevent cylinder 40 from being overloaded.

It must be emphasized that when activated, the locking element 38 shouldabut the tire 8 to press it and lock the chock 1 in place. Such movementof locking element 38 will be within a certain range to facilitateproper positioning against the tire. In case locking element 38 will notbe able to engage the tire, the locking device of chock 1 will signalthis non-safe situation.

Embodiments shown on FIGS. 6 and 7 are not restricted to the lockingarrangement using air pressure mechanism to move locking element 38, andany other suitable means, such as electro-magnetic solenoid orelectrical reversible motor with a rod can be used for the same purpose.

FIG. 8 shows a third embodiment of the present invention comprising thechock 1 and supporting plate 3 similar to the one shown on FIG. 1. Inthis embodiment, wheel chock support means comprise a handle 61 and setof wheels 62 mounted on a side of the chock 1. Chock 1 is moved to theproper position manually by the driver using handle 61 and wheels 62.There are also a set of skis 63 attached beside wheels 62 which may beused during winter season.

The present invention has the following advantages over all knownsystems:

-   -   it is simple and easy to operate due to non-jamming mechanism of        the arm;    -   involves the driver in the safety process;    -   interlocks with dock leveller;    -   arm can be extended up to 14 feet from the loading dock;    -   minimum maintenance is required;    -   galvanized assembly provides excellent durability;    -   non ICC bar dependent;    -   easy snow removal when the arm is stored;    -   presence of highly visible warning system when truck departs        prematurely;    -   anti-theft mechanism preventing unauthorized movement of chock.

Thus, it can be seen that the objects of the present invention have beensatisfied by the structure presented hereinabove. While in accordancewith the Patent Statutes, only the best mode and preferred embodimentsof the present invention have been presented and described in detail, itis to be understood that the invention is not limited thereto orthereby. Accordingly, for an appreciation of the true scope and breadthof the invention, references should be made to the following claims.

1. A wheel chock restraint system, comprising a wheel chock; asupporting element mounted on a ground in a vicinity of a loading dock,a wheel chock support means connected by one end to said wheel chock andby another end in a vicinity of said loading dock, wherein a baseportion of said chock is provided with a first engagement means, whereinsaid first engagement means are directed downwardly outwardly inrelation to said loading dock, and wherein said supporting element isprovided with a corresponding second engagement means, wherein saidfirst engagement means are adapted to cooperate with said secondengagement means thus creating a retention force, said retention forceis directed away from said loading dock and prevents said chock fromsliding away when a vehicle makes an attempt to depart prematurely fromsaid loading dock; wherein said wheel chock support means is adapted toassure a secure positioning of said chock under the wheel of saidvehicle during loading and unloading operation by means of creating anengagement force directed towards said loading dock and pressing saidchock against said wheel; wherein said system comprises an anti-theftlocking means, wherein said locking means together with said first andsecond engagement means are adapted to securely lock said chock on thewheel of said vehicle and to prevent any unauthorized removal of saidchock and theft of said vehicle, and wherein said locking means isactivated remotely by an activating means, said activating means isadapted to lock said locking means against the wheel of said vehicle. 2.A wheel chock restraint system according to claim 1, wherein said firstengagement means comprises a plurality of teeth extending downwardlyfrom said base portion of the chock under a predetermined angle.
 3. Awheel chock restraint system according to claim 2, wherein said chock isplaced on said supporting element in such a way that said teeth aredirected away from said loading dock.
 4. A wheel chock restraint systemaccording to claim 2, wherein said supporting element has aconfiguration of an elongated plate, said plate having a lengthsufficient enough to be spread at least under one axle of said vehicleduring the loading operation to facilitate a proper engagement of saidwheel chock with said plate.
 5. A wheel chock restraint system accordingto claim 4, wherein said second engagement means comprise a number ofstoppers mounted across said plate.
 6. A wheel chock restraint systemaccording to claim 5, wherein said stoppers comprise a plurality of rodshaving a cylindrical configuration.
 7. A wheel chock restraint systemaccording to claim 1, wherein said wheel chock support means is amovable arm comprising a front arm pivotally connected to a rear arm,said front arm is pivotally connected to said wheel chock and said reararm is pivotally connected to a dock face, said movable arm means isprovided with a tension means provided to facilitate an easy placementof said chock under the wheel of said vehicle and to facilitate aplacement of said restraint system into a storage position.
 8. A wheelchock restraint system according to claim 7 wherein said tension meansis a spring connected by one end to said dock face and by another end toan upper portion of said front arm, wherein the more said spring extendsthe more it pulls on said upper portion of said front arm to facilitateproper setting of said chock under the wheel.
 9. A wheel chock restraintsystem according to claim 7, wherein said system further comprises asensor means provided to facilitate a proper placement of said chockunder the wheel of said vehicle.
 10. A wheel chock restraint systemaccording to claim 9, wherein said sensor is mounted within said wheelchock, said sensor is adapted to detect the presence of said wheel inthe moment when said wheel engages said chock.
 11. A wheel chockrestraint system, comprising a wheel chock; a supporting element mountedon a ground in a vicinity of a loading dock; a wheel chock support meansconnected to said chock; wherein a base portion of said chock isprovided with a first engagement means, wherein said first engagementmeans are directed downwardly outwardly in relation to said loadingdock, and wherein said supporting element is provided with acorresponding second engagement means, wherein said first engagementmeans are adapted to cooperate with said second engagement means, thuscreating a retention force that applies no pressure on a wheel of avehicle, said retention force is directed away from said loading dockand prevents said chock from sliding away when said vehicle makes anattempt to depart prematurely from said loading dock; wherein said wheelchock support means is adapted to assure a secure positioning of saidchock under the wheel of said vehicle during loading and unloadingoperation; wherein said system further comprises an anti-theft lockingmeans, wherein said locking means together with said first and secondengagement means are adapted to securely lock said chock on the wheel ofsaid vehicle and to prevent any unauthorized removal of said chock andtheft of said vehicle, and wherein said locking means is activatedremotely by an activating means, said activating means is adapted tolock said locking means against the wheel of said vehicle.
 12. A wheelchock restraint system according to claim 11, wherein said systemfurther comprises a sensor means provided to facilitate a properplacement of said chock under the wheel of said vehicle.
 13. A wheelchock restraint system according to claim 11, wherein said locking meansare adapted to detect said wheel and to transmit a signal indicatingproper positioning of said chock.
 14. A wheel chock restraint systemaccording to claim 10, wherein said sensor means comprising anelectronic sensor, said electronic sensor is adapted to detect saidwheel and to send a signal to a control panel.
 15. A wheel chockrestraint system according to claim 11, wherein said activating means isan air cylinder located in said chock.
 16. A wheel chock restraintsystem according to claim 15, wherein said air cylinder is activated bymeans of a signal transmitted from a remote switch means.
 17. A wheelchock restraint system according to claim 16, wherein said air cylinderis provided with a release valve adapted to release air from saidcylinder thus allowing controlled disengagement of said locking meansfrom said wheel when loading operation is complete and to facilitatelocking of said wheel.
 18. A wheel chock restraint system according toclaim 17, wherein said locking means is provided with an additional airreserve means adapted to compensate changes of pressure applied to saidlocking means during loading and unloading operations.
 19. A wheel chockrestraint system, comprising a wheel chock; a supporting element mountedon a ground in a vicinity of a loading dock; a wheel chock support meansconnected to said chock; wherein a base portion of said chock isprovided with a first engagement means, wherein said first engagementmeans are directed downwardly outwardly in relation to said loadingdock, and wherein said supporting element is provided with acorresponding second engagement means, wherein said first engagementmeans are adapted to cooperate with said second engagement means, thuscreating a retention force that applies no pressure on a wheel of avehicle, said retention force is directed away from said loading dockand prevents said chock from sliding away when said vehicle makes anattempt to depart prematurely from said loading dock; wherein said wheelchock support means is adapted to assure a secure positioning of saidchock under the wheel of said vehicle during loading and unloadingoperation; wherein said system further comprises an anti-theft lockingmeans, wherein said locking means together with said first and secondengagement means are adapted to securely lock said chock on the wheel ofsaid vehicle and to prevent any unauthorized removal of said chock andtheft of said vehicle, and wherein said locking means is furtherprovided with a detector means, said detector means is adapted to beactivated when said locking means does not make necessary contact withthe wheel, thus signalling a non-safe situation.
 20. A wheel chockrestraint system according to claim 19, wherein said locking means isactivated remotely by an activating means, said activating means isadapted to lock said locking means against the wheel of said vehicle.21. A wheel chock restraint system according to claim 20, wherein saidactivating means is an air cylinder located in said chock.